Usage:
3176 Truck Engines
Description of Change: A new valve shield is used which prevents excessive oil slobber during engine idle. The new shield is available either by itself, or preassembled onto the rotocoil. See Illustrations 1 and 2 for the location of the new shield.
Adaptable To: The new 7E7978 Shield is part of the 9Y2760 Basic Cylinder Head Group. If obtained by itself, the smaller diameter of the shield will snap in place into the bottom side of the existing rotocoil. The shield may also be obtained as an assembly. The 7E7977 Rotocoil Assembly contains both the 7C8581 Rotocoil Assembly and the new 7E7978 Shield. See Illustration 2. This change is effective with 3176 (2YG3870) Truck Engine, and is adaptable to first production.
Illustration 1. Cross section of inlet and exhaust valves showing the new shield.
Illustration 2. 7E7977 Rotocoil Assembly. (1) Rotocoil assembly. (2) New shield.